AIRE and autoimmune disease: Critically, specialized subsets of mTEC, including those defined by expression of the autoimmune regulator (Aire) gene, possess the capacity to ectopically express a diverse array of peripheral tissue antigens (PTAs).[21, 22] This, at least in part, endows the medulla with the capacity to negatively select developing autoreactive thymocytes, leading to deletion of clones expressing αβTCRs with high affinity to self‐antigens which could otherwise contribute to autoimmune disorders.